This proposal requests funds to purchase a Zeiss 510 multiphoton/single-photon confocal microscope to be housed in the Department of Biomedical Sciences in the Cornell College of Veterinary Medicine. The goal is to provide a modern, user-friendly fluorescence imaging system for use by PHS-funded researchers located in Biomedical Sciences and other departments within the Veterinary College. The microscope will also become part of the newly established Cornell Imaging Core, a campus-wide initiative to provide state-of-art imaging for all biological and biomedical researchers at the Ithaca campus. As part of the core, the instrument will be made available to PHS-funded researchers from other departments on the Cornell campus as scheduling permits. This equipment is required due to an increase in vivo imaging projects at Cornell involving rodent and transgenic mouse models of disease and pathophysiology. In addition, several other PHS-funded projects that require microscopic imaging of cell cultures will also benefit from the multicolor (single photon) confocal imaging capabilities of the Zeiss 510. Researchers from Biomedical Sciences whose projects involve in vivo imaging are currently using the multiphoton imaging systems of Developmental Resource for Biophysical Imaging and Opto-electronics (DRBIO), which is located in the School of Applied and Engineering Physics at Cornell. DRBIO is funded by NIBIB via the P41 mechanism and is a national Resource, and therefore cannot give priority to Cornell researchers over PHS-funded users from other universities. Recently time on DRBIO's three multiphoton microscopes suitable for in vivo imaging projects has become limited due to high demand. For example, DRBIO has collaborators scheduling time as much as three months in advance. In addition, infrastructure demands of live animal imaging, such as adequate ventilation of anesthesia gases and proximity to specialized facilities for animal surgery have become more difficult to meet due to building constraints and new Environmental Health and Safety requirements. Finally, transportation of transgenic animals between DRBIO and the transgenic mouse facility, located a mile away, creates a constant aggravation. Infrastructure and transportation problems will be completely alleviated by placement of a multiphoton imaging system near the transgenic mouse facility in the Veterinary College.